Oil filter housing gasket

[nigel jarrett]

At the moment I am replacing the oil filter housing but I have a problem getting the correct gasket to go between the housing and crankcase ,all my housings have small oil ways (6mm) where as the club can only supply the ones with a large hole (12mm) which over laps over the edge of the casing ,the gaskets are very thick and of a quite stiff material making the difficult to make ,has anyone any ideas please as the only possible gasket I can use is in two halfs and I am aware this is a very difficult area to make oil tight

[Forumadmin]

There is a lot on JT about modifying this gasket with O rings. https://jowett.club/forum/viewtopic.php?p=15480#p15480
https://jowett.club/forum/viewtopic.php?p=11729#p11729

The original was made of 2mm cork e.g https://www.scooter-center.com/en/cork- ... mm-7673165 which you should be able to get on the internet/local motor factors, although I would probably go for a stiffer material as cork easily squashes and blows out. You might get away with 1.5mm if you use https://uk.rs-online.com/web/p/gasket-sheets/0855923/
Do not forget the felt at the apex.

If you do not have any get a set of hole punches. I always made my own as the stock ones were usually shrivelled and useless.

[David Morris]

Hi Nigel,

You are probably aware that this is a dodgy area of the engine design. Gerald Palmer must have taken his eye off the ball here or perhaps gone home early on a Friday afternoon? As Keith has mentioned, one solution is to go for the 'O' ring option and, if this is your way forward, members, like myself, who have taken this route, would be only too happy to help.

However, if you would like to keep to the original solution, here are a few tips that might help?

a. from the small size of the oil ways, you clearly have an early oil filter housing ( known as the rear timing cover or RTC ). So, for a start, you have size on your side. The oil holes are smaller, probably allowing more width on the gasket and width here, is everything.

b. as a start, I would check that the two securing holes tapped into the crankcase are in good condition and there is no raised ridge around the holes. If there are, they can be reduced carefully with a flat file.

c. using a flat ruler on it's edge, check that the RTC 'wings' are actually flat. Over the years, over-zealous tightening of the two securing bolts ( to try and stop leaks? ) might have distorted the ends of the RTC. Engineer's blue can be used here to check even seating across both faces, where they meet the crankcase. High or low spots on the RTC need to be dressed out.

d. I only use one bolt, fitted to the tapped hole on the driver's side. To help hold the gasket in place, I make up a stud and fit this into the passenger's side tapping. This then helps to locate the gasket and stops it sliding away when you fit the RTC. Make sure the stud is screwed all the way down into the block and preferably secure with thread sealant.

e. to make up a gasket, as Keith suggests, I would first make up a paper pattern, using the underside of the RTC and a soft pencil. You can easily buy gasket material from the internet through eBay. I wouldn't use pure cork, but the rubber composition type, interwoven with cork, seems to work well.

f. If you don't have hole punches, these are also available on eBay very reasonably.

g. I use a smear of gasket sealant ( I use Stag Wellseal, although everyone has their own pet 'goo' ) on the gasket and let it set, as per the instructions.

h. Looking at the five holes drilled through the front timing cover, these carry long thin bolts that locate into the front face of the RTC. There are two problems here. If there isn't enough clearance in these holes, they will prevent the RTC being held down tightly against the crankcase. Also, if these bolts are done up too tight, they will pull the RTC towards the front timing cover, again upsetting the sealing of the RTC gasket. The solution is to open up the diameter of these holes to allow the bolts to move downwards and also, don't tighten them too much. They only need to help form the seal with the Front Timing Cover, which has it's own gasket and is only subject to splash from the timing gears. If you haven't taken the front cover off, you can make up a half-moon shaped gasket to the seal the front cover. [ Jowett's were economical on torque wrench settings. My Jowett WW2 stationary engine workshop manual carried just two instructions on bolt torques...'Tight' or 'Dead Tight'! ]

I do hope it all goes well, and that you have a dry engine. Mine has some kitchen roll stuffed down underneath the oil filter body. Not to help mop up any oil but to give me a warning if there are any incipient leaks since I last looked!

Hope this helps? We are always ready to help with advice, so ask away!

All the best and stay safe,

David

[Forumadmin]

This might help.
https://jowett.net/forum/viewtopic.php?p=23595#p23595

[nigel jarrett]

Thank you on the info and links for this post ,I have now found some 2mm thick gasket paper in the back of the cupboard and after reading the post including the bit about timing chains and checked my new one to find the circling was incorrectly fitted so I am learning a lot about these engines and their quirks

[Mike Allfrey]

I note this topic and venture my solution.

I use an aluminium plate the same outer shape as the gasket. The plate is 1.6 mm thick and I use a new gasket as a template for drilling holes to suit 'O' rings that are the correct inside diameter to match the oil drillings, and have sufficient ring section to squash enough to form an oil tight seal. Two of the oil bores are rather close, but there is room for enough aluminium to form a support for the 'O' rings.

Not a drop of oil has leaked since.

Referring to the bolts, I have found that the depth of thread can be extended into the crankcase and longer bolts employed in cases where the threads have suffered abuse. At the peak of the crankcase joint, I glue a piece of 'O' ring cord with super-glue and, once set, shave the cord so that it squeezes a small amount when the rear timing cover is tightened down.

During an engine's assembly, I first install the front timing cover, less its gasket, and tighten it firmly to the front face of the crankcase set. Then the rear timing cover is installed hard against the front cover, before it is tightened down. That procedure ensures a flat face for the front timing cover gasket when it is installed.

All the best for your project,

Mike Allfrey.

[Keith Clements]

Mike,
A different way to install the oil filter base (rear timing cover) against the front timing cover!
It is important that when tightening the 4+1 bolts that secure the oil filter base to the front timing cover that the base is not pulled at the top, so 10 lbs ft is all that is required.
In the past I have loosely tightened all the front timing cover bolts, then loosely tightened the two base bolts, then loosely tightened the 4+1 bolts. Then tighten till there is still a sliding fit everywhere before tightening the timing cover bolts (except the 4+1), then the base bolts and then the 4+1.
A few times I have had to replace the oil filter base en route before the advent of the O ring solution. This can be done by removing the top (+1) stud to aid extraction of the base.
It would be useful to record how much depth the 2 bolt holes can be extended. Does anybody have a record?

[David Morris]

Hi,

As Keith says, it is very useful to extract the long stud he terms the +1 bolt in the centre of the five fixings for the front cover. This allows you to drop the RTC down onto the crankcase and aids alignment, especially if you are using the 'O' ring gasket technique, where you need to see what is happening as you tighten down. The centre stud can then be fitted later, but it is useful to take off the oil filler pipe, to give yourself more room. Be careful you don't drop the fixing bolt into the sump!

The centre stud and the four adjacent long bolts from the front cover are a bit of a pain, as they can tilt the RTC forward if done up too tight and don't help in making a good seal for the RTC. Again ,as Keith says, these don't need to be tightened any more than around 10lbs/ft. Indeed, before you fit the RTC, we would recommend that you open out the holes for these four +1 bolts and stud in the front cover, to allow the RTC to drop down squarely onto the crankcase face. Give them plenty of clearance, otherwise the RTC can be prevented from going down flush and tight to the crankcase face.

With care and using the 'O' rings ( which should be Vitron to stand the heat ) you can end up with a nice and dry engine, so good luck! Don't be tempted to use 'O' rings that are too thick. Go for one's that give about 0.006" to 0.007" nip. If they are too thick, they will just squeeze out!

All the best and stay safe,

David

[Mike Allfrey]

Good points David.

In my experience the front timing cover bolt holes for the rear timing cover are generous clearance holes to allow downwards movement of the rear cover when the two 5/16-in. bolt and setscrew are tightened. Maybe, earlier front covers did not have generous clearance holes? Increasing the hole size could break through into the coolant jacket, due to severe corrosion?

Good luck with the project,

Mike A.